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From: Chris Faylor <cgf AT cygnus DOT com>
Date: Sun, 25 Jun 2000 18:47:43 -0400
To: cygwin-developers AT sourceware DOT cygnus DOT com
Subject: Re: Introducing slight binary incompatibility in newer executables?
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In-Reply-To: <20000625221009.25276.qmail@web118.yahoomail.com>; from earnie_boyd@yahoo.com on Sun, Jun 25, 2000 at 03:10:09PM -0700

On Sun, Jun 25, 2000 at 03:10:09PM -0700, Earnie Boyd wrote:
>--- Chris Faylor <cgf AT cygnus DOT com> wrote:
>> I am contemplating a change to the cygwin crt0 code that will move some
>> more shared data into the DLL.  I can make the DLL backwards compatible
>> with older executables but making the new executables backwards
>> compatible with older DLLs is not as easy.  So:
>> 
>> DLL		"New" exe	"Old" exe
>> <1.1.3		doesn't work	works
>> >1.1.3		works		works
>> 
>> What's the consensus on this?  We've discussed breaking binary
>> compatibility from time to time.  This is not precisely that bad
>> but it may generate some confused mailing list traffic.
>> 
>> The error will be something like "entry point cygwin_user_data not
>> found".  The solution will be simple: "Upgrade your DLL".
>> 
>> The benefits are smaller user programs and a slightly faster cygwin DLL.
>> 
>
>I'm in favor of anything that adds speed up.  I would suggest a final release
>of the current dll (a 1.1.4) and to increment the minor version so that we
>would get 1.3.0.

I don't think this binary incompatibility is so great that we need to bump
the middle number.  If we do that then we should probably think about other
changes as well and maybe even creating a cygwin2.dll.

Anyway, my initial thought that my changes would speed things up may have
been too optimistic.  The DLL that I've created is 30K larger than the
previous version and I'm not sure why.  I'm investigating now.

cgf